Abstract: Disclosed are a 2-(2,4,5-substituted aniline) pyrimidine derivative, a pharmaceutical composition and a use thereof. The pharmaceutical composition comprises a therapeutically effective amount of the 2-(2,4,5-substituted aniline) pyrimidine derivative, a solvate, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient. Also disclosed is a use of the 2-(2,4,5-substituted aniline) pyrimidine derivative, a solvate, or a pharmaceutically acceptable salt thereof in the preparation of drugs for treating cancers. The compounds of the present invention have a relatively high solubility in water and a relatively high permeability, and/or a relatively low binding ability to plasma proteins, and at the same time have a relatively low toxicity characteristic and a relatively high anti-tumor activity.